Method of producing gel-type inorganic oxide catalysts



United States Patent nice 2,697,066 METHOD OF PRODUCING GEL-TYPEINORGANIC OXIDE CATALYSTS g I Robert sieg, Berkeley, Calif-., assignortoCalifornia Research Corporation, San Francisco, a corporation ofDelaware I No Drawing. ApplicafionDecember 28, 1950, Serial No. 203,19919 Claims. (Cl. 196-=-'50) This invention relates to improvements in thepreparation of gel-type inorganic oxide catalysts for catalyticconversion processes employing elevated temperatures and, articularly,to a method of preparing solid oxide cataysts which are characterized bya high surface area, high degree of porosity, and unusual mechanicalstability.

It has been previously proposed to increase the catalytic activity ofsolid gel-type catalysts by means of incorporating organic compounds andcarbon perse into the catalyst mass during its preparation, and burningout the combustible carbon additive during calcining to effect a higherdegree of porosity. While a certain amount of improvement in catalyticactivity-was gained in such a manner, the improvements did not offsetthe resulting loss in mechanical strength and abrasion resistance.Furthermore, the increased porosity rendered the catalyst mass extremelydifiicult to pelletize or form beads. Accordingly, any increase inconversion of charge attained by the increased porosity of the catalystmass could not practically be realized by reason of its attendantdisadvantages.

It has now been found possible to prepare gel-type oxide catalystswherein the porosity may be controlled to effect an increase inavailable catalytic surface area and produce a catalyst mass whichadditionlly possesses greater mechanical stability and strength and ismore resistant to abrasion and attrition. Besides the unusual mechanicalstability and desirable pelle'tizing properties, the catalysts preparedin accordance with the invention possess a greater catalytic selectivityin that they promote higher yields of liquid conversion products and apronounced reduction in secondary reactions which lead to tar, coke andgas formation. This increase in catalytic selectivity for the primaryreaction is attributed to improved diffusional transfer of reactants andproducts, as well as an inherent difference in the porous and catalyticnature of the gel :catalysts produced according to this invention.-

These unusual achievements in catalyst preparation are generallyapplicable to those catalyst compositions which are formulated with asynthetic gel-type inorganic oxide as an active catalyst or catalystsupport material. In-' eluded within the classification are the activeoxides of silicon, aluminum, chromium, molybdenum, magnesium,

iron, vanadium, manganese, copper, nickel, titanium, N thorium,zirconium, and tungsten.- as well as others which are recognized aspossessing catalytic activity in'tlie conduct of organic conversionprocesses. These catalyst bases may be used individually or incombination with one another as plural oxide catalysts or catalyst basesand may be coprecipitated with or impregnated on a precipitated activeoxide base.- One requirement of the present preparation process is thatat least one of the active gel-type oxide components of the catalyst comosition or base be formed by precipitation from a soluble salt oroxide-convertible compound of its element.

It has been discovered that when a gel-type inorganic oxide isprecipitated from a solution containing a controlled amount of dissolvedor dispersed high molecular weight combustible organic material, acatalyst composi-' tion may be produced which not only possessesexceptional catalytic properties. but also includes unusual mechanicalstability and pelletizing characteristics; It has been ascertained thatthe molecular weight and amount of the organic material used in theprecipitationof the hydrous oxide is a controlling factor intheregulation of the available active surface, degree and type of porosity,mechanical strength characteristics and resultant activity andselectivity of the finished catalyst. The desired physicalcharacteristics of the catalyst are dependent upon the catalystcomposition nd the particular type ofcatalyt'ie conversion process inwhich it' is to be employed.

2,697,066 Patented Dec. 14, 1954 Broadly, the improvements in catalystactivity obtained by the subject preparation process are applicable tothe production of solid catalysts for such conversion processes asdehydrogenation, hydrogenation, cracking, reforming, desulfurization,dehydration, isomerization, cyclizauon, etc., as well as specialmodifications thereof, wherein the conversion of an organic charge iseffected or at least promoted by contact in the vapor or liquid phasewith a solid oxide catalyst at elevated temperatures. The preparation ofthese catalysts proceeds in substantially the conventional manner exceptfor the initial precipitation of the hydrous gel. The organic materialwhich is occluded within the gel structure may be partially decomposedduring the initial drying stage when the gel structure is established,and is wholly removed by oxidation in the calcining of the catalyticoxide.

In order to effect the modification and improvement in catalyststructure and associated activity; the precipitation is conducted in thepresence of a water-dispersible, high molecular weight, organic materialwhich is present in amounts ranging from about 3 to 30% by weight, basedupon the anhydrous oxide content of the catalyst. The particular optimumamount of organic material used is dependent upon the molecular weightof the organic material, the composition of the catalyst, and the typeof improvement desired, e. 'g., increased surface area, increaseddiffusional transfer, increased selectivity, etc-., provided that withinthis range the amount of organic material is insufficient in and ofitself to set up into a gel gtructilre during the precipitation of theinorganic hyroge organic material uniformly distributed as the internalphase during the precipitation of the' oxide gel and avoid organic gelformation when employing gel-forming organic materials. The molecularweight of the organic materials is dependent upon the type of conversionprocess to which the catalyst composition is applied and especially themolecular weight of the organic charge to the conversion process. As ageneral proposition, it has been found that organic materials having amolecular weight within the 'ran'g'e of about 1X10 to l l0 have proveneffective in the preparation of catalyst composi tions for conversionprocesses charging stocks ranging from C4 to about C20 or from a butanefraction to heavy gas oil. These organic materials may consist of substantially uniform compounds or polymers or, as is gener-' ally the casein materials of this molecular weight range, of a mixture of compoundsor naturally occurring compositions whose molecular weights extend overa substantial range. In the latter instance, reference is made to themean or-apparent molecular weight of the mixed organic materials ofvarying molecular or particle weights.

The types of high molecular weight organic materials found suitable forthe purposes of the invention, and par ticularly within the preferredmolecular weight range of about 1 l0 to 1x10 include such materials asthe various animal and vegetable proteins, cellulosic materials andderivatives thereof, high molecular weight carbohydrates, alcohols, andesters, as well as certain natural and synthetic aqueous emulsions orcolloids, such as the rubber latices, microscopic livingorganisms,bacteria, molds, etc.

The choice of the materials within the prescribed molec ular weightrange will depend upon their solubility or dispersibility in theprecipitation solution and a reasonable stability during the drying stepwhen the inorganic gel structure is established. Although a partialdecomposition of the organic material during the drying step may betolerated, substantial decomposition will negate the ef fect of theorganic additive for the purposes f the invention. The initial dryingstep must necessarily be con ducted at elevated temperatures of at leastabout 150 F. in order to appreciate the improvement in catalyststructure attained by the invention process. During this initial dryingstage,- the crystalline or lattice structure of the inorganic oxide baseis established, and any interference through the formation of an organicgel structure is definitely to be avoided. As a precaution in thisregard, the amounts of organic additive employed in the precipitationstep should be insufficient to form an organic gel in- .the ease ofthose organic materials which possess gel- It is of particularimportance to maintain the.

the inorganic oxide gel and results in a low-density oxide base ofinadequate stability.

, As previously stated, the organic material is applied to theprecipitation step in the form of an aqueous dispersion in order toobtain uniform phase distribution within the inorganic gel structure.This aqueous dispersion may be either physical or molecular, as in thecase of colloids, suspensions, and solutions. In conducting theprecipitation of the inorganic hydrogel, the pH of the precipitatingsolution is controlled to not only effect the precipitation, but also toavoid coagulation of 1' the organic additive. This optimum pH isvariable and depends upon the type of hydrogel precipitated and in somecases the isoelectric point of the organic additive.

It has been ascertained that or anic materials possessing a molecularweightbelow 1x10 such as the simple sugars and the like. do not effectany material improvement .in the available catalytic surfaces of theinorganic gel catalysts. On the other hand, organic materials having anapparent weight greater than 1 10 and particularly such materials whichhave been ground to fine powders, increase the gel porosit decrease thephysical strength and have no measurable effect on total gel surfacearea or usef cat lytic surface as evidenced by activity. As anillustrati n of the magnitude of the molecular or apparent weights offine powders, 200-mesh organic particles ha e an ap arent particleweight of approximatel 1X10; and 10 weight per cent of such powderedadditive, if completely effective. wou d increase the el surface ar onlya few hundredths f a square meter per gram. On the other hand. 10 weightper cent -1' of the organic additive materials within the molecularweight r n es herein s ecified have been found to cause substantialincre ses in the resultant measurab e surface area of the oxide gels, fr example, 10 to 100 square meters er gram. and such increa es are ofeven greater proport l value in catalytic effectiveness because of theav ilab lit of he active surface resulting from such mo ecular-sized addives.

Ex erimental evidence indic tes that the m ecular wei ht of the organicadditive for optimum effectiveness of catalvs structures in organicconversion processes is subst n iall ropo ionate to the molecular wei htof the feed stock. Thus. in general, for the purp se of obtai ing i ceased effectiveness a d rticularly increased avail b e catalyt csurface, it is desirable to conduct the precipitation f the inorganic elin the presence of an organic mate i l who e molecular or particle weihts r nge from 10 to 10 times he molecular Weight of he char e stock tobe processed.

The amounts of or anic m terials or additive employed Wi hin the r ngeof 330% by Weight based up n anhvdrous oxide conte t will preferablyvary with the individual organic addit e and the particular ty e ofconversion process in which the catal st is employed. When usingel-formin or nic ma erials. the con entration of additive should'he keptbelow the gel-f rming concentra ions at the preci itation temperature.Ouantities less than 3% by wei ht do not result in si ificant chan es ingel structu e. while quantities above by wei ht frequently vield over yporous els which are mechanically unstable and difficult'to utilize incommercial p ocess s. n i s over-all application, amounts rangin from10-20% by wei ht are generally referred. Within this ran e the mehanical stren th of the granular or beaded organic additive el catalystsare substanti lly superior to the non-add tive con rol gels. Also, withthe compress n-pelleted type catalysts, those produced from the additiveels show a lower bulk density, yet materially higher pellet strengththan the non-addi ve control cat lysts. Such increases in mechanicalstabi ity.

and strength serve as further evidence of the modified surface structureof the gels, and are of considerable value in c mmercial processes wherecatalyst abrasion and attrition impose limitations on the process. Inthe preparation of gel-type cracking catalysts, a considerabledifference in appearance and properties is evident when utilizing thesubject organic additives. Thus, the nonadditive control gels aretransparent and show a marked tendency to shatter on impact, whereas theadditive gels are opaque granules with an increased resistance to impactfracture.

As illustrative of the effect of type of conversion process and chargestock upon optimum molecular weight range and amount of organicmaterial, the comparison between the catalytic reforming of petroleumnaphthas and the catalytic cracking of gas oils is presented. Thus, inthe catalytic reforming of petroleum naphthas with ground and pelletedcatalyst, it is preferred to effect the preparation of the catalyst inthe presence of 5-15 by weight of protein additives such as gelatins andglues having molecular Weights ranging from 10,000 to 100,000; while inthe catalytic cracking of gas oil with beaded or large granularcatalysts, higher percentages and higher molecular weights of additiveswere found to give optimum effectiveness, as, for example, l025% byweight of additives having molecular or particle weights materiallyabove 100,000, such as cellulose derivatives, rubber latex, dried skimmilk, etc.

In order to obtain a more detailed perspective of the improved catalystsand catalyst bases prepared in accordance with the process of theinvention, numerous prep arations were made and tested to determine theeffect of molecular weight and amount of organic additive upon catalystimprovement in representative conversion processes and varying catalystcompositions. The sub sequent general methods of catalyst preparationare presented as representative of the methods used. It is to beunderstood that certain modifications of these methods were necessary inthe preparation of other metal base catalysts.

The following represents the preparation of a granular coprecipitatedsilica-alumina catalyst gelled in the presence of 20 per cent of naturalrubber latex solids which may be used as a cracking catalyst.

1035 grams of Grade N sodium silicate (equivalent to 300 grams silica)was diluted to three liters and adjusted to a pH of 10 by adding dilutesulfuric acid. 200 cc. of natural rubber latex (equivalent to 66 gramsof rubber solids) was diluted to one liter and added with stirring,followed by rapid addition of one liter of dilute aluminum chloridesolution containing the equivalent of 33.3 grams of alumina. Thesolution thickened and set to a stiff inorganic gel in 10-20 seconds. Atthe time of gelation the concentration of rubber solids was 1.1 weightper cent, an amount insufficient to result in coagulation or organic gelformation. The SiO2Al2O3 concentration was 5.5 Weight per cent, which issutficient for formation of a semisolid inorganic oxide gel structure.The gel was repulped with 3 liters of additional water to give a thickslurry, adjusted to a pH of 7 by adding ammonium hydroxide, andfiltered. The filter cake was repulped with water to six liters volumeand filtered five times, keeping the pH of the thick slurry between 5and 6 by adding HCl or NH lOH when necessary. The final filter cake wasplaced in a drying oven at 210 F. until the gel dried to hard,glass-like granules. These granules were then calcined in air at 1100 F.to burn out the organic additive.

In addition, the following illustrates the preparation of acoprecipitated molybdena-alumina catalyst precipitated in the presenceof 10 weight per cent of dissolved animal glue, which was pelleted foruse in a dehydrogenation or reforming process.

70 grams of brown flake animal glue having a molecular weight ofapproximately 60,000 was dissolved by heating in one liter of water andadded to 8 liters of dilute aluminum chloride solution containing theequivalent of 600 grams of anhydrous alumina. grams of M003 dissolved inone liter of dilute ammonium hydroxide was then added with stirring,followed with 2 liters of concentrated NH4OH diluted with 2 liters ofwater. Complete coprecipitation of the Moos-A1203 resulted. The thickslurry was repulped, adjusted to a pH of 7 and filtered. At the time ofcoprecipitation the glue concentration was 0.5 weight per cent, anamount insuflicient to result in coagulation or organic gel formation,and the MOO3-Al203 concentration was 5 per cent. The fil er cake waspartially dried then repulped to 14 liters with water and filtered threetimes for removal of most of the ammonium chloride. The filter cake was15 .then placed in a drying oven at321- for 48.-hours.:to permit settingof thegel structure. The :dried' cake was then ground and pelleted bycompression :into A-ginch pills, using 4 per cent of graphite lubricant.Thepelleted .6 tives such as of a partially hydrolyzed starch with amolecular weight ofabout 15,000.

An accentuation of the improvements in catalyst composition is borne outin a comparison of the carbon-burncatalyst was then calcinedby heatingslowly 'in air to 5 ing rates during regeneration which'is presently alimita- ;1-18.0 F. and then held at this temperatureqfor four tion inthe design and operation of many catalytic conhours to insure completeoxidation and removal of the version processes and is emphasized incatalytic'cracking. organic additive. The final catalyst analyzed 1:1.6weight The following tabular data indicates the higher burning per centof M003, some being lost to solution during rates obtained whenemploying the additive catalysts washing. 1.0 and particularly thepreferred higher molecular weight Implementing the coprecipitated pluraloxide :gels, additives in the preparation of coprecipitated SiOz-AlzOxothelr preparations were carried out ciln bwhich an active crackingcatalysts. cata yst component was inco orate im re nation I of thecalcined oxidebase of the invent ion 5s, %orex- Regenemtw" after ATestmg ample, the impregnation of an improved alumina base [Excess airat wiith ammgniii m thmolybdatei1 chromate,f alnd chlorop atinic aci urermore,t eprocesso t e invention Rubber u11ml. Rubber was also appliedin the preparation of beaded or Organ Addmve j Lat x lu Nomi Latexspherical catalyst compositions.

Organic materials of varying molecular or particle Weightporcent 20 2 2Qweights were used in these specific preparations. The APPIOX-IHOLWt250,000 r 250,000 effective additives within the molecular weight rangeof igg gg ggggfgg' ff about 1X10 to 1X10 included the starches ofvarying iterdegrees of hydrolysis, animal proteins, glues, gelatins,39.6 36.1 32.5 6-7 pectin, water-soluble derivations ofpropylene-polymers, 52-; 52-2 33-3 35-3 dried skim milk, rubber latex,methyl cellulose,v and dispersed natural cellulose. These additives wereemployed in varying concentrations within the range of 330% by Theincreased carbon burning rates as demonstrated weight based upon theanhydrous oxide content of the with the organic ad ti e ype Catalyst isa Particular catalyst base, advantage in the conventional catalyticcracking processes. As an illustration of the eifectiveness of thepresent With s yp of Catalysis existing P121Hts could'operate method ofpreparing inorganic oxide catalysts and cataon greatercoke producing.feeds or utilize higher catalyst lyst bases, a number of representativedata are presented circulation rates and higher conversion levels onpresent showing some of the aforementioned. catalytic improvefeedsWithout exceeding their capacity for adequate regenments as applied tothe conventional conversion process. crflfion 0f Coked y- In theevaluation of cracking catalysts prepared according As a .furtherillustration of the practical application of to this invention, a seriesof granular silica-alumina crackthese improved catalyst compositions,additional data are ing catalysts prepared in the presence of varyingconcenpresented onhydroforming operations which involve catatrations oforganic additives were subjected to a'standard ly-tic reforming anddehydrogenation. The test upon Cat. A cracking activity 'test incomparison with non- 40 which the. following comparative results wereobtained additive control catalysts. This test was conducted at wasconducted on a heavy Mid-Continent naphtha stock 800' F. on a light EastTexas gas oil with a 200 cc. cata having an F-l :octane number of 57.0,at 200 p. s. i. g., lyst charge and a IO-minute on-stream time.Representaa 1.0 v./v./hr.. space rate with 6,000 cu. ft./bbl. of processtive results are as follows: gas recycle and l-hour on-stream period.Activity testing Table I Dried Rub Organic Additive None ,Rubber LatexSkim bet Milk Latex Weight Percent 20 15 15 Approx. Mol.Wt 250, 000200,000 250,000 Bulk Density 0.90 0.59 0.55 0. 44 Surface Area-MJ/gr 216315 353 324 Oat.ATest: Run Run Runv 1' Run Space rate, v./v./h1' 1.5 3.01.5 3.0 1.5 1.5 Yields:

Carbon, wt. percent 4. 75 3.00 4.88 2. 41 4.02 3. 56 Gas, wt. percent...10. 75 5.72 11. 47 6.83 10.10 9. 50 Gasoline, wt. percen 40. 6 32. 746.1 36.7 42. 3 43. 7 Gasoline/Coke ratio 8.6 10.9 9.5 15.2 10.5 12.3

Additional results obtained using 15% "by weight of was done at twotemperatures to give comparable data an animal glue of a molecularweight of about 50,000 on the catalysts over a range of conversionlevels. The and 15% by weight of a gelatin whose molecular weightparticular .series of catalyst compositions tested were was about 75,000showed an increase in catalytic activity pelleted molybdena-aluminacatalysts prepared in the presover the control but not as great animprovement in gasoence of varying molecular weights and amounts oforganic line-to-coke ratio as was obtained using the highermolecuadditives and with molybdena concentrations varied in lar weightadditives. An improvement in catalytic activity an efiort to obtainapproximately uniform activity on conwas also obtained with even lowermolecular weight addistant octane number product at these testconditions.

Table II- [Inlet temperature, 925 F.]

Organic additive None Gelatin Glue ggf g Pectin Weight percent 10 10 101'0 Approx. M01. Wt 00, 000 10,000 25,000 40, 000 M003, Weight percent11.35 (15 10th Octane Number oi Prod. (C; coppt copp copp copp free) F-lclear 89.8 91.0 39.9 88.& 88.2 -ss-.5 Carbon produced, grams 6. 92 3.344. 41 3.03 3. 38 3. 47 Product yields:

Carbon, wt. percent 1.7 I 0.8 1.1 0.8 0.9 0.9 Gas, wt. percent-.. 11.09.1 7.7 7.1 9,6 7.]. Liquid, wt.percent 87.3 v 90.1 01.2 I 92.1 89.592.0

Table III {Inlet Temperature, 955 F.]

Organic Additive None Gelatin Gelatin Glue Weight percent 1 l5 Approx.mol. wt 80, 000 60, 000 M003, Weight percent 12. 11. 10. 0 l0. 5 eopptd.copptd impreg. copptd. Octane Number of Product (C4 free) F-l clear 94.5 94. 2 95. 8 95. 2 Carbon produced, grams... 11.58 8. 6 5. 60 4. 61,Product yields:

Carbon, wt. percent" 2. 9 2. 2 1. 4 1. 2 Gas, wt. percent 12. 1 11. 112. 2 12.0 Liquid, wt. percent" 85. 0 86. 7 86.4 86. 8

As will be noted from the foregoing data, the catalysts prepared in thepresence of the organic additives all indicate a considerableimprovement in liquid product yields with a marked reduction in theamount of coke produced. Additional data have indicated that the highermolecular weight additives, such as those appreciably above 100,000,although resulting in a high activity catalyst, do not effect the samedegree of coke reduction as the lower molecular weight additives.

Obviously, many modifications and variations of the invention ashereinabove set forth may be made Without departing from the spirit andscope thereof, and only such limitations should be imposed as areindicated in the appended claims.

I claim:

1. A process for producing improved gel-type oxide catalysts suitablefor use in high temperature catalytic hydrocarbon conversion processeswhich comprises mixing an aqueous solution of an inorganic compoundcapable of yielding a hydrous oxide gel when precipitated, and anaqueous dispersion of a water-dispersible organic material having amolecular weight within the range of 1 10 to 1x10 said organic materialbeing present in an amount within the range of 3% to 30% by weight basedupon the content of said inorganic compound in said mixture calculatedas anhydrous oxide, said organic material being present in insufficientconcentration to form an organic gel, adding a precipitant to saidmixture to precipitate said hydrous oxide gel containing water solublesalts formed during the precipitation, washing said non-gel phase, thensubjecting the washed hydrous oxide gel to an initial drying stepconsisting of heating at a temperature of at least about 150 F.but'below a temperature at which substantial decomposition of theorganic material occurs, sufficient to establish the lattice structureof the inorganic oxide and to prevent formation of an organic gelstructure while the inorganic oxide lattice structure is beingestablished, and then calcining the dehydrated oxide gel to decomposeand remove the organic material, thereby to produce a stable, highlyporous, high surface area catalyst.

2. A process for producing improved plural gel-type oxide catalystssuitable for use in high temperature catalytic hydrocarbon conversionprocesses which comprises mixing an aqueous solution of at least two inorganic compounds capable of yielding hydrous oxides when precipitated,and an aqueous dispersion of a water-disnersible organic material havinga molecular weightwithin the range of 1x10 to 1X10", said organicmaterial being present in an amount within the range of 3% to 30% byWeight based upon the content of said inorganic compounds in saidmixture calculated as anhydrous oxides, but in insufficientconcentration to form an organic gel, precipitating a plural hydrousoxide gel containing water soluble salts formed during theprecipitation, washing said hydrous oxide gel to remove said watersoluble salts, the hydrous oxide gel forming the external phase and theorganic material being present as an internally dispersed, non-gelphase. then subjecting the washed hydrous oxide gel to an initial dryingstep consisting of heating at a temperature of at least about 150 F. butbelow a temperature at which substantial decomposition of the organicmaterial occurs, sufiicient to establish the lattice structure of theinorganic oxide and to prevent formation of an organic gel structurewhile the inorganic oxide lattice structure is being established, andthen calcining the dehydrated oxide gel to decompose and remove theorganic material, thereby to produce a stable, highly porous, highsurface area plural oxide catalyst.

3. A process which comprises catalytically reforming petroleum naphthato produce gasoline which comprises contacting said naphtha at reformingconditions with the catalyst of claim 1.

4. The process as described in claim 1 wherein the metal oxide catalystcomprises aluminum and molybdenum oxides.

5. The process as described in claim 1 wherein the metal oxide catalystcomprises aluminum oxide.

6. The process as described in claim lwherein the metal oxide catalystcomprises silicon and aluminum oxides.

7. The process as described in claim 1 wherein the organic material isanimal glue.

8. The process as described in claim 1 wherein the oxide catalystcomprises aluminum and molybdenum oxides, and wherein the organicmaterial has a molecular weight in the range of about 10,000 to about100,000.

9. The process as described in claim 1 wherein the metal oxide catalystcomprises aluminum and molybdenum oxides and wherein the organicmaterial is animal glue.

10. A hydrocarbon reforming catalyst made in accordance with the processof claim 1.

11. A hydrocarbon reforming catalyst made in accordance with the processof claim 8.

12. A hydrocarbon reforming catalyst made in ac cordance with theprocess of claim 9.

13. The process as described in claim 3 wherein the oxide catalystcomprises aluminum and molybdenum oxides.

14. The process as described in claim 3 wherein the oxide catalystcomprises aluminum and molybdenum oxides, and wherein the organicmaterial has a molecular weight in the range of about 10,000 to about100,000.

15. The process as described in claim 14 further characterized in thatthe organic material is animal glue.

16. A process of catalytically cracking a hydrocarbon oil whichcomprises subjecting said oil to cracking conditions in the presence ofan improved gel type metal oxide catalyst made by precipitating ahydrous metal oxide in the presence of an aqueous dispersion of awater-dispersible organic material to produce a hydrous metal oxideexternal gel phase containing said organic material having a molecularweight within about the range 1 10 to 1X10 distributed therein as aninternal dispersed phase, said organic material being present in anamount within about the range of 3 to 30 per cent by weight, based onanhydrous oxide, but in an insufficient concentration to form an organicgel, Washing said hydrous metal oxide gel to remove inorganicwater-soluble salt material formed during precipitation, and thenheating the washed oxide gel containing dispersed organic material to atemperature of at least about F. sufficient to establish the latticestructure of the inorganic oxide and to prevent formation of an organicgel structure and to dehydrate the oxide gel, then calcining thedehydrated oxide gel to decompose and remove the organic material, andto produce a stable, highly porous, high-surface-area catalyst.

17. The process substantially as described in claim 16 wherein the oxidecatalyst comprises aluminum and silicon oxides.

18. The process substantially as described in claim 16 wherein the oxidecatalyst comprises aluminum and silicon oxides, and wherein the organicmaterial has a molecular weight of at least about 100,000.

19. The process substantially as described in claim 18 furthercharacterized in that the organic material is natural rubber latexsolids.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,976,875 Connolly Oct. 16, 1934 2,317,803 Reeves Apr. 27,1943 2,337,628 Schulze Dec. 28, 1943 2,384,945 Marisic Sept. 18, 1945(Other references on following page) Number 9 UNITED STATES PATENTS NameDate Gunness Oct. 29, 1946 Foster Oct. 14, 1947 5 Tamele et a1. Nov. 23,1948 Messenger May 24, 1949 Number Name Y Date Haensel Aug. 16, 1949Claussen et 21 Sept. 13, 1949 Ehrhardt Dec. 6, 1949 Plank Mar. 7, 1950Schmerling Oct. 24, 1950

1. A PROCESS FOR PRODUCING IMPROVED GEL-TYPE OXIDE CATALYSTS SUITBLE FORUSE IN HIGH TEMPERATURE CATALYTIC HYDROCARBON CONVERSION PROCESSES WHICHCOMPRISES MIXING AN AQUEOUS SOLUTION OF AN INORGANIC COMPOUND CAPABLE OFYIELDING A HYDROUS OXIDE GEL WHEN PRECIPITATED, AND AN AQUEOUSDISPERSION OF A WATER-DISPERSABLE ORGANIC MATERIAL HAVING A MOLECULARWEIGHT WITHIN THE RANGE OF 1X103 TO 1X107, SAID ORGANIC MATERIAL BEINGPRESENT IN AN AMOUNT WITHIN THE RANGE OF 3% TO 30% BY WEIGHT BASED UPONTHE CONTENT OF SAID INORGANIC COMPOUND IN SAID MIXTURE CALCULATED ASANHYDROUS OXIDE, SAID ORGANIC MATERIAL BEING PRESENT IN INSUFFICIENTCONCENTRATION TO FORM AN ORGANIC GEL, ADDING A PRECIPITANT TO SAIDMIXTURE TO PRECIPITATE SAID HYDROUS OXIDE GEL CONTAINING WATER SOLUBLESALTS FORMED DURING THE PRECIPITATION, WASHING SAID HYDROUS OXIDE GEL TOREMOVE SAID WATER SOLUBLE SALTS, THE HYDROUS OXIDE GEL FORMING THEEXTERNAL PHASE AND THE ORGANIC MATERIAL BEING PRESENT AS AN INTERNALLYDISPERSED, NON-GEL PHASE, THEN SUBJECTING THE WASHED HYDROUS OXIDE GELTO AN INITIAL DRYING STEP CONSISTING OF HEATING AT A TEMPERATURE OF ATLEAST ABOUT 150* F. BUT BELOW A TEMPERATURE AT WHICH SUBSTANTIALDECOMPOSITION OF THE ORGANIC MATERIAL OCCURS, SUFFICIENT TO ESTABLISH TOLATTICE STRUCTURE OF THE INORGANIC OXIDE AND TO PREVENT FORMATION OF ANORGANIC GEL STRUCTURE WHILE THE INORGANIC OXIDE LATTICE STRUCTURE ISBEING ESTABLISHED, AND THEN CALCINING THE DEHYDRATED OXIDE GEL TODECOMPOSE AND REMOVE THE ORGANIC MATERIAL, THEREBY TO PRODUCE A STABLE,HIGHLY POROUS, HIGH SURFACE AREA CATALYST.